Broadly, acousto-optically modulated laser beam scanning systems, particularly raster scanning systems, are old, and several satisfactory system arrangements are known. As the art progresses, however, the increasing demands relative to speed, resolution and registration, together with the demands on impact printing, paper toning and fusing, bring about some rather difficult problems in advancing the art. Wherever possible, it is highly desirable that conventional methods and conventional apparatus be used, if for no other reason than these methods and this apparatus has individually proven its worth in past performance.